Construction Classics

Operations records — two reports, 1964 and 1970

Almost everything else in this collection describes a machine being designed or built. These two describe machines being run, by the people running them, in the period before anyone wrote a retrospective. That is a different and scarcer kind of document: nobody writes an operations report to be instructive, so nothing in it is arranged to flatter the machine.

The most useful table in either report

NRL accounted for every hour of a six-month period. Of 1,382.5 scheduled hours the cyclotron operated 831.3, or 60.1%; outage took 551.2 hours, or 39.9%. A further 360 hours of engineering shutdown sit outside that budget. Of the operating time, 518.7 hours were beam on target — so beam actually reached a target for about 38% of scheduled time, and the rest went to adjustment, target setup and development.

What stops a cyclotron is the part worth reading twice:

Power supplies and vacuum together account for 19.5% of scheduled time; the RF accounts for 1.6%. The RF system is the subsystem amateur builders worry about most, write about most, and rebuild most often. On a machine that ran for six months it was the twelfth most expensive thing to own, behind the mechanical plant and only just ahead of changing the source filament.

Read the ranking, not the percentages. This is a large 1960s facility with a professional operating staff, a demineralised cooling plant and a 200 hp standby water pump; a tabletop machine has a different failure distribution and far fewer hours to lose. What transfers is which class of subsystem consumes the time, and the discipline of keeping the ledger at all — you cannot know your own distribution without recording it.

Harvard, four days lost, and what lost them

The Harvard quarterly opens on the machine before it gets to the physics, and the first paragraph is the whole argument for reading operations records:

During the past quarter, the cyclotron was in operation 1680 hours, or about 18 hours per day. Three days were lost due to failure of the refrigerator for the cold-trap above the diffusion pumps. Another day was lost because of inadequate oil levels in the diffusion pumps.

Four days of a working cyclotron, and both causes are vacuum-plant housekeeping — a failed cold-trap refrigerator and diffusion-pump oil that was allowed to run low. Neither appears in any design document, because neither is a design problem. They agree with NRL's ledger, from a different machine in a different decade, that the vacuum system is where the time goes.

The rest of the report is the experimental programme — quasi-free proton-proton scattering, and biological irradiations including patients with diabetic retinopathy and brain tumours, which places this among the early proton-therapy records. A. M. Koehler, who signs the machine section, ran the Harvard cyclotron for decades and is a significant figure in that history.

Why these documents can be hosted

NRL Memorandum Report 2103 is the strongest rights position in the collection: the Naval Research Laboratory is a United States Government laboratory, so the report is a work of the US Government and carries no copyright. Its cover states This document has been approved for public release and sale; its distribution is unlimited. No copyright notice, classification marking or distribution restriction appears in 39 pages.

The Harvard quarterly needs its own reasoning, because a university report is not a work of the US Government — and this one was supported by a NASA grant rather than written by federal employees. The basis here is publication before 1978 without a copyright notice. Under the Copyright Act of 1909, publishing without notice put a work into the public domain, and this copy carries direct evidence of publication: the Defense Documentation Center’s sale stamp, HARD COPY $1.00 / MICROFICHE $0.50, alongside its accession stamp of 23 October 1964. It was distributed and offered for sale to the public. No copyright notice appears in its ten pages.

That is a stronger form of the same argument used for the MSUCP reports, where the pre-1978 basis rested on the absence of a notice alone; here there is affirmative evidence of public distribution. Determinations made August 2026, by reading the scans.

The two reports

1. Report of Cyclotron Operation, 1 July – 31 December 1969
   Cyclotron Staff, Cyclotron Branch, Nuclear Physics Division. Report of Cyclotron Operation, 1 July – 31 December 1969, NRL Memorandum Report 2103. Naval Research Laboratory, Washington DC, March 1970.
   A sector-focusing cyclotron reported the way an operating facility reports itself: the research programme it served, the engineering changes made during the period, and an hour-by-hour accounting of where the time went.
   Download PDF — 1.9 MB, 39 pages · DTIC AD-0705484
2. Quarterly Progress Report, 1 June – 31 August 1964
   Cyclotron Laboratory, Harvard University. Quarterly Progress Report, 1 June – 31 August 1964. A. M. Koehler and colleagues. Supported in part by NASA Grant NsG-262-63.
   Ten pages from the Harvard cyclotron, opening with the machine section rather than the physics: hours run, days lost, and what lost them. The rest is the experimental programme, including some of the earliest proton-beam medical irradiations.
   Download PDF — 0.56 MB, 10 pages · DTIC AD-0607226

About these copies

Both are Defense Technical Information Center scans of typescript originals, and their text layers are unreliable on digits in a way that matters here, because these documents are mostly numbers. The NRL ledger renders 831.3 as 851.3, 128.6 as 028.6 and 140.4 as lto.lt; the Harvard cover renders 1964 as 196*+. Every figure quoted on this page was read from the page image, and anyone quoting others should do the same. A wrong digit here is not visibly corrupt — it is a plausible number that happens to be false, which is the worst kind.

Design rules from these documents

20 Design Guide rules come from the pair, concentrated in operations, vacuum and maintenance practice rather than design.

Companion reading: the commissioning practice cluster covers the period before these reports begin, and the 22-inch test cyclotron follows one small machine through construction and operation across three and a quarter years of quarterlies.